433 
MINES OF BATTLE MOUNTAIN, EAST GROUP. 
deep, lies 1,900 feet a little west of north from the Burns shaft and 1,300 feet nearly 
north-northwest from the No. 2 shaft; it is on the north slope of Battle Mountain, 
just below the summit, and its collar is 250 feet above that of the Burns shaft. An 
adit over 3,100 feet in length enters Battle Mountain near the collar of the Burns 
shaft and connects with the No. 2 and No. 3 shafts at about 162 and 250 feet below 
the surface, respectively. Through this adit timbers are taken in to these shafts 
and ore run out to the ore house near the Burns shaft. 
Besides the shafts mentioned are a number of old openings, such as the Anna 
Lee, Bobtail, Diamond, Scranton, and Wisconsin shafts, formerly worked as inde¬ 
pendent mines, but at present serving only for ventilation, and two small shafts, 
the Colorado City and Hawkeye, near the north end of the property, which have 
recently been connected with the main Portland workings. Since the time of visit 
the Lowell shaft, northwest of the Burns shaft, has been sunk to a depth of 170 
feet, and stopes have been opened on three levels. 
The principal levels now worked are designated as follows, the figures referring 
to the collar of the Burns shaft: The adit level, the 220-foot level, the 350-foot level, 
the 500-foot level, and thence levels at intervals of approximately 100 feet down 
to the 1,100-foot level. An idea of the general plan and extent of these levels 
may be had from figs. 56 and 57. 
GEOLOGICAL FEATURES. 
The workings of the Portland mine are partly in the breccia and eruptive rocks 
of the Cripple Creek volcanic neck and partly in the encircling granite through 
which these volcanic materials were ejected and intruded. (See PI. V, p. 26.) 
The granite is of the Pikes Peak type, 0 such as underlies the town of V'ctor and is 
exposed on Squaw Mountain. It is petrographically described on pages 43 to 45 
a Mathews, E. B., The granites of Pikes Peak, Colorado: Bull. Geol. Soe. America, vol. 6, 1894, p. 472. See also 
Geology and mining industries of the Cripple Creek district, Colorado: Sixteenth Ann. Rept. U. S. Geol. Survey, pt. 2, 
1895, pp. 22-23. 
